function Game(el){
    this.el = document.querySelector(el)

    //地图
    this.map=new Map(this.el)
    this.map.create()

    //食物
    this.food = new Food(this.el)
    this.food.create()

    //蛇
    this.snake = new Snake(this.el)
    this.snake.create()
}
Game.prototype.start=function(){
    
    setInterval(()=>{
        this.snake.move()
        let snakeX = this.snake.snakeObj[0].x*20
        let snakeY = this.snake.snakeObj[0].y*20
        let foodX = this.food.foodX
        let foodY = this.food.foodY
        if(snakeX ==foodX &&snakeY==foodY){
            let last = this.snake.snakeObj[this.snake.snakeObj.length-1]
            this.snake.snakeObj.push({
                x:last.x,
                y:last.y,
                color:last.color,
                el:null
            })
            this.snake.create()
            this.food.move()
        }
    },150)
    document.addEventListener('keydown',(e)=>{
        e=e||window.event
        console.log(e.keyCode)
        switch(e.keyCode){
            case 38:
                this.snake.direction='top'
                break;
            case 40:
                this.snake.direction='bottom'
                break;
            case 37:
            // if(this.snake.direction=='right'){
            //     alert('游戏结束')
            // }
                this.snake.direction='left'
                break;
            case 39:
                this.snake.direction='right'
                break;
            default:
                break;
            
        }
    })
}